The center of gravity of a golf club head is one critical parameter of the club's performance. Upon impact, it greatly affects launch angle and flight trajectory of a struck golf ball. Thus, much effort has been made over positioning the center of gravity of golf club heads. To that end, current driver and fairway wood golf club heads are typically formed of lightweight, yet durable materials, such as steel or titanium alloys. These materials are typically used to form thin club head walls. Thinner walls are lighter, and thus result in greater discretionary weight, i.e., weight available for redistribution around a golf club head. Greater discretionary weight allows golf club manufacturers more leeway in assigning club mass to achieve desired golf club head mass distributions.
Various approaches have been implemented for positioning discretionary mass about a golf club head. Many club heads have integral sole weight pads cast into the head at predetermined locations to lower the club head's center of gravity. Also, epoxy may be later added to the interior of the club head through the club head's hosel opening to obtain a final desired weight of the club head. To achieve significant localized mass, weights formed of high-density materials have been attached to the sole. With these weights, the method of installation is critical because the club head endures significant loads at impact with a golf ball, which can dislodge the weight. Thus, such weights are usually permanently attached to the club head and are limited in total mass. This, of course, permanently fixes the club head's center of gravity.
Golf swings vary among golfers, but the total weight and center of gravity location for a given club head is typically set for a standard, or ideal, swing type. Thus, even though the weight may be too light or too heavy, or the center of gravity is too far forward or too far rearward, the golfer cannot adjust or customize the club weighting to his or her particular swing. Rather, golfers often must test a number of different types and/or brands of golf clubs to find one that is suited for them. This approach may not provide a golf club with an optimum weight and center of gravity and certainly would eliminate the possibility of altering the performance of a single golf club from one configuration to another and then back again.
Moreover, the addition of localized weights to a golf club head can cause undesirable acoustic effects in the head upon impact. Additionally, such weights can decrease the durability of the golf club head by creating localized stress concentrations in the head.
Accordingly, there is a need for a system for adjustably weighting a golf club head that allows a golfer to fine-tune the club head to accommodate his or her swing without causing significant adverse effects on the acoustic properties or durability of the club head. The present application fulfills this need and others.